US6169944B1 - Microcomputer-built-in, on-vehicle electric unit - Google Patents

Microcomputer-built-in, on-vehicle electric unit Download PDF

Info

Publication number
US6169944B1
US6169944B1 US09/129,707 US12970798A US6169944B1 US 6169944 B1 US6169944 B1 US 6169944B1 US 12970798 A US12970798 A US 12970798A US 6169944 B1 US6169944 B1 US 6169944B1
Authority
US
United States
Prior art keywords
information
electric unit
vehicle
microcomputer
operating condition
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US09/129,707
Other languages
English (en)
Inventor
Satoshi Hayasaka
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Alps Alpine Co Ltd
Original Assignee
Alps Electric Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Alps Electric Co Ltd filed Critical Alps Electric Co Ltd
Assigned to ALPS ELECTRIC CO., LTD. reassignment ALPS ELECTRIC CO., LTD. ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: HAYASAKA, SATOSHI
Assigned to ALPS ELECTRIC CO., LTD. reassignment ALPS ELECTRIC CO., LTD. ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: HAYASAKA, SATOSHI
Application granted granted Critical
Publication of US6169944B1 publication Critical patent/US6169944B1/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06F—ELECTRIC DIGITAL DATA PROCESSING
    • G06F11/00—Error detection; Error correction; Monitoring
    • G06F11/07—Responding to the occurrence of a fault, e.g. fault tolerance
    • G06F11/14—Error detection or correction of the data by redundancy in operation
    • G06F11/1402—Saving, restoring, recovering or retrying
    • G06F11/1415—Saving, restoring, recovering or retrying at system level
    • G06F11/1441—Resetting or repowering

Definitions

  • the present invention relates to microcomputer-built-in, on-vehicle electric units, and more specifically, to a microcomputer-built-in, on-vehicle electric unit in which stored information in a memory section can be maintained by easy and inexpensive means when the microcomputer is reset because the voltage of an on-vehicle power supply which drives the on-vehicle unit is reduced for some reason.
  • a product inspection test generally includes an item in which, even if the voltage of an on-vehicle power supply (battery) which drives the on-vehicle air conditioner is reduced for several milliseconds to several seconds, information indicating the operating condition which specifies an operating state immediately before the voltage reduction shall be maintained.
  • An on-vehicle air conditioner which satisfies specifications, including such an item, is produced.
  • An on-vehicle electric unit for example, an on-vehicle air conditioner usually includes a manual-operation section formed of a pushbutton operating member for selecting an air outlet, a pushbutton operating member for making a selection from in-vehicle air circulation and ventilation, and a sliding operating member for selecting an inside-vehicle temperature.
  • a CPU is also mounted to efficiently control the on-vehicle air conditioner, and a random access memory (RAM) and a read only memory (ROM) are also provided together with the CPU to serve as a microcomputer as a whole. Operation setting information specified when the manual-operation section is operated, and information indicating the operating condition of the on-vehicle air conditioner at automatically-set setting information are stored in the RAM.
  • the automatically-set setting information refers to automatically-specified setting information such as a setting in which a front-face outlet is automatically selected as an air outlet when the on-vehicle air conditioner serves as a cooling system (cooling), and a setting in which a lower outlet is automatically selected as an air outlet when the on-vehicle air conditioner serves as a heater (heating).
  • FIG. 5 is a block diagram of such a known on-vehicle air conditioner provided with a countermeasure against a voltage drop of an on-vehicle power supply.
  • this on-vehicle air conditioner includes a one-chip microcomputer 50 formed of a central processing unit (CPU) 51 , a RAM 52 , and a ROM 53 , an input and output circuit 54 which includes a manual-operation section, an air-feeding compressor, and a temperature control mechanism, a regulator 55 connected to a power supply for adjusting a power-supply voltage, a reset circuit 56 for detecting a voltage drop of the output voltage of the regulator 55 and generating a reset signal to the CPU 51 , and a backup circuit 57 formed of a diode 58 connected in series and a large-capacitance capacitor 59 shunt-connected.
  • CPU central processing unit
  • RAM 52 random access memory
  • ROM 53 read-only memory
  • an input and output circuit 54 which includes a manual-operation section, an air-feeding compressor, and a temperature control mechanism
  • a regulator 55 connected to a power supply for adjusting a power-supply voltage
  • a reset circuit 56 for detecting a voltage drop
  • the large-capacitance capacitor 59 in the backup circuit 57 is always charged to have the voltage of an on-vehicle power supply (battery, not shown). If the voltage of the on-vehicle power supply is reduced for some reason, for example, due to an activation of a starter motor, a voltage drop is compensated for by discharging the charged voltage of the large-capacitance capacitor 59 to prevent the output voltage of the regulator 55 from being reduced.
  • FIG. 6 is a block diagram of another known on-vehicle air conditioner provided with a countermeasure against a voltage drop of a power supply.
  • this on-vehicle air conditioner differs from the on-vehicle air conditioner shown in FIG. 5 in that the backup circuit 57 is removed and an electrically erasable programmable read-only memory (EEPROM) 60 is provided instead.
  • EEPROM electrically erasable programmable read-only memory
  • FIG. 6 the same symbols as those used in FIG. 5 are assigned to the same elements as those shown in FIG. 5, and descriptions thereof will be omitted.
  • information indicating an operating condition is stored in the EEPROM 60 as well as in a RAM 52 at the same time. If the voltage of an on-vehicle power supply is reduced for some reason, a CPU 51 reset due to a voltage drop reads the information indicating the operating condition stored in the EEPROM 60 and stores it into a RAM 52 . Therefore, the information indicating the operating condition is always stored in the RAM 52 substantially.
  • an object of the present invention is to provide a microcomputer-built-in, on-vehicle electric unit which can maintain information indicating an operating condition stored in a RAM if a voltage of an on-vehicle power supply is reduced, without any special hardware with a least cost increase.
  • a RAM generally maintains its stored contents even if its power voltage drops for a short period of time. This short-time voltage drop in which the RAM maintains its stored contents is defined as a momentary interruption.
  • a microcomputer-built-in, on-vehicle electric unit including: a microcomputer formed of a RAM which stores information indicating an operating condition of the on-vehicle electric unit and momentary-power-supply-interruption check information, a ROM which stores an operation program of the microcomputer, an initial value for the information indicating the operating condition, and the momentary-power-supply-interruption check information, and a CPU which controls the on-vehicle electric unit according to the information indicating the operating condition and the operation program; and a reset circuit which resets the microcomputer if a voltage of an on-vehicle power supply which drives the on-vehicle electric unit is reduced, wherein the microcomputer checks whether the momentary-power-supply-interruption check information stored in the RAM remains when the microcomputer is reset by the reset circuit; when the momentary-power-supply-interruption check information is detected, the microcomputer determines that a momentary interruption of the
  • the microcomputer since the momentary-power-supply-interruption check information is stored in the RAM, the microcomputer detects whether the momentary-power-supply-interruption check information stored in the RAM remains if the voltage of the on-vehicle power supply drops, and the microcomputer determines that a momentary power-supply interruption has occurred when the momentary-power-supply-interruption check information is detected, or the microcomputer determines that not a momentary power supply interruption but a voltage drop lasting for a time period exceeding that of a momentary interruption has occurred when the momentary-power-supply-interruption check information is not detected, special hardware, such as the backup circuit and the EEPROM, is not required, and thereby the number of components is reduced, the structure becomes simple, assembling becomes easy, and the production cost is reduced.
  • special hardware such as the backup circuit and the EEPROM
  • a microcomputer-built-in, on-vehicle electric unit including: a RAM which stores one or more sets of copied information obtained by copying at a constant time interval information indicating an operating condition of the on-vehicle electric unit; a ROM which stores an operation program of a microcomputer and an initial value for the information indicating the operating condition; a CPU which controls the on-vehicle electric unit according to the information indicating the operating condition and the operation program; and a reset circuit which resets the microcomputer, including the RAM, the ROM, and the CPU, if a voltage of an on-vehicle power supply for the on-vehicle electric unit is reduced, wherein the microcomputer checks the contents of the one or more sets of copied information stored in the RAM when the microcomputer is reset by the reset circuit; when the contents match the specified information contents, the microcomputer determines that: a momentary interruption of the on-vehicle power supply has occurred and restarts controlling the on
  • the microcomputer checks whether one or more sets of copied information stored in the RAM have the specified information contents when the voltage of the on-vehicle power supply drops; if the specified information contents are satisfied, it is determined that a momentary interruption of the on-vehicle power supply has occurred; and if the specified information contents are not satisfied, it is determined that not a momentary interruption of the on-vehicle power supply but a voltage drop lasting for a time period exceeding that of a momentary interruption has occurred, special hardware, such as the backup circuit and the EEPROM, is not required, and thereby the number of components is reduced, the structure becomes simple, assembling becomes easy, and the production cost is reduced.
  • the microcomputer-built-in, on-vehicle electric unit may be configured such that the on-vehicle electric unit serves as an on-vehicle air conditioner, and the information indicating the operating condition includes information indicating a selected air outlet in the on-vehicle air conditioner, a selection from in-vehicle air circulation and ventilation, and an operating condition of a compressor which determines the amount of output air.
  • FIG. 1 is a block diagram of a microcomputer-built-in, on-vehicle electric unit according to a first embodiment of the present invention.
  • FIG. 2 is a flowchart showing an outlined operation state of the microcomputer-built-in, on-vehicle electric unit shown in FIG. 1 according to the first embodiment.
  • FIG. 3 is a flowchart showing an outlined operation state of the microcomputer-built-in, on-vehicle electric unit shown in FIG. 1 according to a second embodiment.
  • FIG. 4 shows procedures for creating two sets of copied information, for checking whether a momentary interruption has occurred, and for creating copied information at a momentary interruption in the second embodiment.
  • FIG. 5 is a block diagram of a known on-vehicle air conditioner provided with a countermeasure against a voltage drop of a power supply.
  • FIG. 6 is a block diagram of another known on-vehicle air conditioner provided with a countermeasure against a voltage drop of a power supply.
  • FIG. 1 is a block diagram showing a configuration of an on-vehicle electric unit in which a microcomputer is built according to a first embodiment of the present invention.
  • the on-vehicle electric unit serves as an on-vehicle air conditioner in this embodiment.
  • the on-vehicle air conditioner is provided with a one-chip microcomputer 1 formed of a central processing unit (CPU) 2 , a random access memory (RAM) 3 , and a read only memory (ROM) 4 , a manual-operation section 5 , a controlled section 6 , a regulator 7 , and a reset circuit 8 .
  • a starter motor 9 and an on-vehicle power supply (battery) 10 are connected to the on-vehicle air conditioner.
  • the manual-operation section 5 is disposed in a front panel of the on-vehicle air conditioner and includes a pushbutton operating member for selecting an air outlet, a pushbutton operating member for making a selection from in-vehicle air circulation and ventilation, and a sliding operating member for specifying the temperature of a supply air and the amount of air.
  • the manual-operation section 5 is connected to the microcomputer 1 through an I/O line.
  • the controlled section 6 forms an input and output section which includes an air compressor and a temperature control mechanism for a circulating air, and is connected to the microcomputer 1 through an I/O line.
  • the regulator 7 is inserted into a power supply circuit of the microcomputer 1 and adjusts the output voltage of the on-vehicle power supply (battery) 10 .
  • the reset circuit 8 generates a reset signal when it detects a reduction in the output voltage of the regulator 7 , and sends the signal to the CPU 2 .
  • the starter motor 9 is connected between the output terminals of the on-vehicle power supply 10 . When the starter motor 9 is driven, a high current flows through it.
  • the RAM 3 stores momentary-power-supply-interruption information, information indicating the operating condition of the on-vehicle air conditioner, including operation setting information and automatically-set setting information, and other pieces of information
  • the ROM 4 stores an operation program for operating the CPU 2 .
  • the automatically-set setting information refers to automatically-specified setting information such as a setting in which a front-face outlet is automatically selected as an air outlet when the on-vehicle air conditioner serves as a cooling system (cooling), and a setting in which a lower outlet is automatically selected as an air outlet when the on-vehicle air conditioner serves as a heater (heating).
  • the momentary-power-supply-interruption check information is used for determining whether the power supply of the microcomputer 1 has been momentarily interrupted.
  • the CPU 2 When the on-vehicle air conditioner is turned on, the CPU 2 writes the momentary-power-supply-interruption check information into a part of a memory area in the RAM 3 , preferably at both top and bottom of the memory area, and the information is stored there.
  • the contents of the momentary-power-supply-interruption check information are not specified, but they need to be not affected by noise. For example, an information pattern in which a plurality of binary codes, 0's and 1's, are disposed alternately in the horizontal direction and the vertical direction in a memory area, namely, a check pattern is used.
  • the information indicating the operating condition needs to be maintained in the RAM 3 according to the specifications when the power supply is momentarily interrupted.
  • the information includes the automatically-set setting information, and operation setting conditions in the manual-operation section, namely, operation setting information indicating an operation setting condition for an air outlet, an operation setting condition for in-vehicle air circulation or ventilation, and an operation setting condition for the temperature of a supply air and the amount of air.
  • operation setting information indicating an operation setting condition for an air outlet
  • an operation setting condition for in-vehicle air circulation or ventilation an operation setting condition for the temperature of a supply air and the amount of air.
  • the CPU 2 When the on-vehicle air condition is turned on, the CPU 2 writes the information indicating the operating condition into a memory area for the information in the memory area in the RAM 3 , and the information is stored there.
  • the other pieces of information includes various pieces of information (data) sequentially obtained when the CPU 2 controls the on-vehicle air conditioner and additional information (data). The CPU 2 writes these pieces of
  • FIG. 2 is a flowchart indicating a general operation state of the on-vehicle air conditioner according to the first embodiment.
  • the CPU 2 controls the controlled section 6 (normal control processing) based on the operation setting information and the other pieces of information stored in the RAM 3 according to the operation program stored in the ROM 4
  • the starter motor 9 of the on-vehicle air conditioner is driven and an instantaneous high current flows through the starter motor 9 or an instantaneous high current flows through a circuit section other than the starter motor 9
  • the output voltage of the on-vehicle power supply 10 is instantaneously reduced much due to its internal resistor, for example, for about one second, and the reduced voltage is supplied to the regulator 7 .
  • the reduced voltage is supplied to the regulator 7 .
  • the regulator 7 compensates the supplied voltage for its reduction to some extent. If the voltage drop is relatively large, sufficient compensation cannot be performed.
  • the regulator 7 outputs a reduced voltage and supplies it to the microcomputer 1 (CPU 2 , RAM 3 , and ROM 4 ) and to the reset circuit 8 .
  • the reset circuit 8 detects a reduction in the power supply voltage, generates a reset signal, and sends it to the CPU 2 of the microcomputer 1 .
  • the CPU 2 is reset by the sent reset signal and starts operating according to the flowchart shown in FIG. 2 .
  • a step S 1 the CPU 2 checks whether the momentary-power-supply-interruption check information stored in advance in the RAM 3 remains as is irrespective of a reduction in the power-supply voltage.
  • the CPU 2 finds according to the check that the momentary-power-supply-interruption check information has not remained as is (N), the CPU 2 determines that not a momentary power-supply interruption but a voltage drop lasting for a time period exceeding that of a momentary interruption has occurred. In other words, it is determined that all information stored in the RAM 3 is deleted or changed, and the procedure proceeds to the next step S 2 .
  • the CPU 2 determines that a momentary power-supply interruption has occurred. In other words, it is determined that all information stored in the RAM 3 remains, and the procedure proceeds to a step S 4 .
  • the CPU 2 initializes the memory area in the RAM 3 for the information indicating the operating condition to delete all the information indicating the operating conditions, which has been deleted or changed, and writes the initial settings.
  • the CPU 2 overwrites the momentary-power-supply-interruption check information into the memory area in the RAM 3 for the momentary-power-supply-interruption check information to store it.
  • the momentary-power-supply-interruption check information stored in the ROM 4 is used.
  • step S 4 since the CPU 2 cannot use the other pieces of information stored in the RAM 3 due to its reset, the CPU 2 initializes the memory area in the RAM 3 for the other pieces of information to delete all the other pieces of information, and writes the initial settings.
  • a step S 5 the CPU 2 stores the momentary-power-supply-interruption check information, the information indicating the operating condition, and the other pieces of information into the RAM 3 . Since the contents stored in the RAM 3 return to the condition obtained before the voltage reduction of the on-vehicle power supply occurred, the CPU 2 restarts a control operation of the controlled section 6 (normal control processing). In this point of time, specifically, the settings of various switches in the on-vehicle air conditioner are read, the values of various sensors are read, and the information of motor control, relay control, and a display device (LED) and setting information are read.
  • LED display device
  • the microcomputer detects whether the momentary-power-supply-interruption check information stored in the RAM 3 remains if the voltage of the on-vehicle power supply drops; and the CPU 2 determines that a momentary power supply interruption has occurred when the momentary-power-supply-interruption check information is detected, or the CPU determines that not a momentary power supply interruption but a voltage drop lasting for a time period exceeding that of a momentary interruption has occurred when it is found that the momentary-power-supply-interruption check information has been deleted or changed, unlike the known on-vehicle air conditioner, neither the backup circuit nor the EEPROM is required, and thereby the production cost is reduced.
  • a circuit configuration in the second embodiment is the same as that shown in FIG. 1 .
  • a RAM 3 stores one or more sets of copied information and other pieces of information
  • the ROM 4 stores an operation program for operating a CPU 2 .
  • One or more sets of copied information is obtained by copying the information indicating the operating condition at a constant time interval while the CPU 2 performs control of the controlled section 6 (normal control processing).
  • the CPU 2 updates the copied information copied from the information indicating the operating condition at a constant time interval, and always stores one or more sets of the obtained latest copied information into the RAM 3 .
  • one or more sets of the copied information are substituted for the momentary-power-supply-interruption check information used in the first embodiment.
  • FIG. 3 is a flowchart indicating a general operation state of the on-vehicle air conditioner according to the second embodiment.
  • FIG. 4 shows procedures for creating two sets of copied information, for checking if momentary interruption has occurred, and for creating copied information at momentary interruption in the second embodiment.
  • the CPU 2 controls the controlled section 6 (normal control processing) based on the information indicating the operating condition and other pieces of information stored in the RAM 3 according to the operation program stored in the ROM 4 , the CPU 2 creates two sets of copied information at a constant time interval.
  • a procedure for creating the two sets of copied information will be described below by referring to the copy procedure shown in FIG. 4 .
  • the information indicating the operating condition namely, the information indicating the operating condition which needs to be maintained in the RAM 3 at momentary interruption of the power supply
  • A, B, and C two rolling codes assigned to two sets of copied information obtained in the previous time are set to R 1O and R 20
  • two rolling codes assigned to two sets of copied information obtained at this time are set to R 11 and R 21 , which are incremented by 1 from the codes R 10 and R 20 .
  • a first set of copied information includes one rolling code, R 11 , at this time, stored in a memory area “r 1 ” in the RAM 3 , the information indicating the operating condition, A, B, and C stored in memory areas, “a 1 ,” “b 1 ,” and “c 1 ,” confirmation information obtained by inverting the sum of the information indicating the operating condition, A, B, and C, stored in a memory area “s 1 ,” and one rolling code R 11 stored in a memory area “e 1 ,” in the same way as in the memory area “r 1 .”
  • a second set of copied information includes the other rolling code, R 21 , at this time, stored in a memory area “r 2 ” in the RAM 3 , the information indicating the operating condition, A, B, and C stored in memory areas, “a 2 ,” “b 2 ,” and “c 2 ,” confirmation obtained by inverting the sum of the
  • the output voltage of the on-vehicle power supply 10 is instantaneously reduced much due to its internal resistor, for example, for about one second, and the reduced voltage is supplied to the regulator 7 .
  • the reduced voltage is supplied to the regulator 7 .
  • the regulator 7 compensates the supplied voltage for its reduction to some extent. If the voltage drop is relatively large, sufficient compensation cannot be performed.
  • the regulator 7 outputs a reduced voltage and supplies it to the microcomputer 1 (CPU 2 , RAM 3 , and ROM 4 ) and to the reset circuit 8 .
  • the reset circuit 8 detects a reduction in the power supply voltage, generates a reset signal, and sends it to the CPU 2 of the microcomputer 1 .
  • the CPU 2 is reset by the sent reset signal and starts operating according to the flowchart shown in FIG. 3 .
  • a step S 11 the CPU 2 checks whether the two sets of copied information stored in the RAM 3 have the specified information contents described later, irrespective of a reduction in the power-supply voltage.
  • the CPU 2 finds according to the check that the two sets of copied information does not have the specified information contents (N)
  • the CPU 2 determines that not a momentary power-supply interruption but a voltage drop lasting for a time period exceeding that of a momentary interruption has occurred. In other words, it is determined that all information stored in the RAM 3 has been deleted or changed, and the procedure proceeds to the next step S 12 .
  • the CPU 2 finds that the two sets of copied information have the specified information contents (Y)
  • the CPU 2 determines that a momentary power-supply interruption has occurred. In other words, it is determined that all information stored in the RAM 3 remains, and the procedure proceeds to a step S 13 .
  • Whether the two sets of copied information have the specified information contents is checked separately for each of the two sets of copied information. For example, it is performed in the following way.
  • the CPU 2 detects for the first set of copied information that the memory contents stored at the memory area “r 1 ” and at the memory area “e 1 ” in the RAM 3 match and that the memory contents stored in the memory area “s 1 ” match the confirmation information obtained by inverting the sum of the information indicating the operating condition, a 1 , b 1 , and c 1 . When these match conditions are satisfied, the CPU 2 determines that the specified information contents are satisfied.
  • the CPU 2 detects for the second set of copied information that the memory contents stored at the memory area “r 2 ” and at the memory area “e 2 ” in the RAM 3 match and that the memory contents stored in the memory area “s 2 ” match the confirmation information obtained by inverting the sum of the information indicating the operating condition, a 1 , b 1 , and c 1 .
  • the CPU 2 determines that the specified information contents are satisfied. If the above match conditions are not satisfied for each of the first and second sets of copied information, it is determined that the specified information contents are not satisfied.
  • the CPU 2 determines that all information stored in the RAM 3 has been deleted or changed.
  • the CPU 2 initializes the memory area in the RAM 3 for the information indicating the operating condition to delete all the information indicating the operating condition, which has been deleted or changed, and writes the initial settings.
  • a step S 13 even if it is determined that a momentary interruption of the power supply has occurred, since either the first set or the second set of copied information stored in the RAM 3 may have been deleted or changed, the CPU 2 recovers either the first set or the second set of copied information in the following way.
  • the pieces of information stored in the memory areas “a 1 ,” “b 1 ,” and “c 1 ” in the RAM 3 are copied onto the memory areas A, B, and C in the RAM 3 , respectively, and the pieces of information stored in the memory areas “r 1 ,” “a 1 ,” “b 1 ,” “c 1 ,” “s 1 ,” and “e 1 ” in the RAM 3 are copied onto the memory areas “r 2 ,” “a 2 ,” “b 2 ,” “c 2 ,” “s 2 ,” and “e 2 ” in the RAM 3 , respectively.
  • the pieces of information stored in the memory areas “a 2 ,” “b 2 ,” and “c 2 ” in the RAM 3 are copied onto the memory areas A, B, and C in the RAM 3 , respectively, and the pieces of information stored in the memory areas “r 2 ,” “a 2 ,” “b 2 ,” “c 2 ,” “s 2 ,” and “e 2 ” in the RAM 3 are copied onto the memory areas “r 1 ,” “a 1 ,” “b 1 ,” “c 1 ,” “s 1 ,” and “e 1 ” in the RAM 3 , respectively.
  • next step S 14 since the CPU 2 cannot use other pieces of information stored in the RAM 3 due to its reset, the CPU 2 initializes the memory area in the RAM 3 for the other pieces of information to delete all the other pieces of information, and writes the initial settings.
  • a step S 15 since the contents stored in the RAM 3 return to the condition obtained before the voltage drop of the power supply occurred, the CPU 2 restarts a control operation of the controlled section 6 (normal control processing).
  • the CPU 2 checks whether the two sets of copied information stored in the RAM 3 have the specified information contents when the voltage of the on-vehicle power supply drops; if the specified information contents are satisfied, it is determined that a momentary interruption of the on-vehicle power supply has occurred; and if the specified information contents are not satisfied, it is determined that not a momentary interruption of the on-vehicle power supply but a voltage drop lasting for a time period exceeding that of a momentary interruption has occurred, unlike the known on-vehicle air conditioner, neither the backup circuit nor the EEPROM is required, and thereby the number of components is reduced, the structure becomes simple, assembling becomes easy, and the production cost is reduced.
  • the on-vehicle electric unit serves as an on-vehicle air conditioner.
  • An on-vehicle electric unit according to the present invention is not limited to an on-vehicle air conditioner. It is a matter of course that an on-vehicle electric unit similar to the on-vehicle air conditioner may be used.
  • the information indicating the operating condition to be maintained in the RAM 3 if the power supply is momentarily interrupted includes information indicating an operation setting condition for an air outlet in the on-vehicle air conditioner, an operation setting condition for in-vehicle air circulation or ventilation, and an operation setting conditions for the temperature of a supply air and the amount of air.
  • the information indicating the operating condition of an on-vehicle air conditioner according to the present invention is not limited to those pieces of information. It is a matter of course that the information may include other pieces of information.
  • the two sets of copied information are stored in the RAM 3 .
  • the number of copied information sets is not limited to two, but may be just one.

Landscapes

  • Engineering & Computer Science (AREA)
  • Theoretical Computer Science (AREA)
  • Quality & Reliability (AREA)
  • Physics & Mathematics (AREA)
  • General Engineering & Computer Science (AREA)
  • General Physics & Mathematics (AREA)
  • Power Sources (AREA)
  • Techniques For Improving Reliability Of Storages (AREA)
  • Air-Conditioning For Vehicles (AREA)
US09/129,707 1997-08-05 1998-08-05 Microcomputer-built-in, on-vehicle electric unit Expired - Lifetime US6169944B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP9-210710 1997-08-05
JP21071097A JP3701776B2 (ja) 1997-08-05 1997-08-05 マイクロコンピュータ搭載の車載電装機器

Publications (1)

Publication Number Publication Date
US6169944B1 true US6169944B1 (en) 2001-01-02

Family

ID=16593827

Family Applications (1)

Application Number Title Priority Date Filing Date
US09/129,707 Expired - Lifetime US6169944B1 (en) 1997-08-05 1998-08-05 Microcomputer-built-in, on-vehicle electric unit

Country Status (4)

Country Link
US (1) US6169944B1 (fr)
EP (1) EP0896276B1 (fr)
JP (1) JP3701776B2 (fr)
DE (1) DE69810027T2 (fr)

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20030104847A1 (en) * 2001-11-30 2003-06-05 Terutaka Maruyama Transmitter device having means for automatically transmitting data remaining therein upon its re-activation
US20060184827A1 (en) * 2005-02-15 2006-08-17 Robinson Timothy A Method for responding to a control module failure
US20070127178A1 (en) * 2005-12-01 2007-06-07 Takashi Yoneda Semiconductor device
US20090040843A1 (en) * 2007-08-06 2009-02-12 Sandisk Corporation, A Delaware Corporation Enhanced write abort mechanism for non-volatile memory
US20090157254A1 (en) * 2005-09-09 2009-06-18 Sharp Kabushiki Kaisha Steerable vehicle information display system, as well as cockpit module and steerable vehicle incorporating the system
US20110210951A1 (en) * 2008-10-27 2011-09-01 Lifescna Scolland Limited Methods and Devices for Mitigating ESD Events
US20110225434A1 (en) * 2007-10-09 2011-09-15 Masaru Nishikawa Microcomputer controller
US20140053030A1 (en) * 2012-08-16 2014-02-20 Hyundai Motor Company Method and system for preventing loss of trip data in vehicle
US11500848B2 (en) * 2017-07-20 2022-11-15 Continental Automotive France Method for determining the integrity of navigation data of a control unit of an automotive vehicle

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP4883282B2 (ja) * 2006-06-01 2012-02-22 株式会社デンソー 車載用電子機器制御装置
JP2008291769A (ja) * 2007-05-25 2008-12-04 Toyota Motor Corp アクチュエータの制御装置
JP5184994B2 (ja) * 2008-07-02 2013-04-17 新電元工業株式会社 電源瞬停記憶装置、ａｃ−ｄｃコンバータ及び電源瞬停記憶方法
JP2010195221A (ja) * 2009-02-25 2010-09-09 Nsk Ltd 電動パワーステアリング装置
JP5317865B2 (ja) * 2009-07-07 2013-10-16 キヤノン株式会社 画像形成装置
JP5721786B2 (ja) * 2013-07-09 2015-05-20 キヤノン株式会社 画像形成装置

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0213577A2 (fr) 1985-08-23 1987-03-11 Sony Corporation Appareil pour la sauvegarde de données lors d'une coupure de l'alimentation dans un téléviseur contrôlé par micro-ordinateur
EP0393631A2 (fr) 1989-04-20 1990-10-24 Sanyo Electric Co., Ltd Processus initial après coupure de la source d'alimentation et système de traitement correspondant
US4972340A (en) * 1985-07-10 1990-11-20 Hitachi, Ltd. Engine control system
US4994934A (en) * 1989-12-01 1991-02-19 Abb Power T & D Company Inc. Microcomputer based reclosing relay
US5227981A (en) * 1989-04-20 1993-07-13 Sanyo Electric Co., Ltd. Initial process system after cutoff of power source and process system at the time of cutoff of power source
US5983146A (en) * 1995-12-27 1999-11-09 Valeo Climatisation Electronic control system for a heating, ventilating and/or air conditioning installation for a motor vehicle

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4972340A (en) * 1985-07-10 1990-11-20 Hitachi, Ltd. Engine control system
EP0213577A2 (fr) 1985-08-23 1987-03-11 Sony Corporation Appareil pour la sauvegarde de données lors d'une coupure de l'alimentation dans un téléviseur contrôlé par micro-ordinateur
US4750040A (en) * 1985-08-23 1988-06-07 Sony Corporation Apparatus controlled by a micro-computer and including power loss data checking
EP0393631A2 (fr) 1989-04-20 1990-10-24 Sanyo Electric Co., Ltd Processus initial après coupure de la source d'alimentation et système de traitement correspondant
US5227981A (en) * 1989-04-20 1993-07-13 Sanyo Electric Co., Ltd. Initial process system after cutoff of power source and process system at the time of cutoff of power source
US4994934A (en) * 1989-12-01 1991-02-19 Abb Power T & D Company Inc. Microcomputer based reclosing relay
US5983146A (en) * 1995-12-27 1999-11-09 Valeo Climatisation Electronic control system for a heating, ventilating and/or air conditioning installation for a motor vehicle

Cited By (17)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6959181B2 (en) 2001-11-30 2005-10-25 Denso Corporation Transmitter device having means for automatically transmitting data remaining therein upon its re-activation
US20030104847A1 (en) * 2001-11-30 2003-06-05 Terutaka Maruyama Transmitter device having means for automatically transmitting data remaining therein upon its re-activation
US20060184827A1 (en) * 2005-02-15 2006-08-17 Robinson Timothy A Method for responding to a control module failure
US7406624B2 (en) * 2005-02-15 2008-07-29 General Motors Corporation Method for responding to a control module failure
DE102006006843B4 (de) * 2005-02-15 2018-02-08 General Motors Corp. Verfahren zum Antworten auf einen Steuermodulausfall
US8082077B2 (en) 2005-09-09 2011-12-20 Sharp Kabushiki Kaisha Steerable vehicle information display system, as well as cockpit module and steerable vehicle incorporating the system
US20090157254A1 (en) * 2005-09-09 2009-06-18 Sharp Kabushiki Kaisha Steerable vehicle information display system, as well as cockpit module and steerable vehicle incorporating the system
US20070127178A1 (en) * 2005-12-01 2007-06-07 Takashi Yoneda Semiconductor device
US7479817B2 (en) 2005-12-01 2009-01-20 Panasonic Corporation Semiconductor device
US7599241B2 (en) * 2007-08-06 2009-10-06 Sandisk Corporation Enhanced write abort mechanism for non-volatile memory
US20090040843A1 (en) * 2007-08-06 2009-02-12 Sandisk Corporation, A Delaware Corporation Enhanced write abort mechanism for non-volatile memory
US20110225434A1 (en) * 2007-10-09 2011-09-15 Masaru Nishikawa Microcomputer controller
US20110210951A1 (en) * 2008-10-27 2011-09-01 Lifescna Scolland Limited Methods and Devices for Mitigating ESD Events
US8994395B2 (en) 2008-10-27 2015-03-31 Lifescan Scotland Limited Methods and devices for mitigating ESD events
US20140053030A1 (en) * 2012-08-16 2014-02-20 Hyundai Motor Company Method and system for preventing loss of trip data in vehicle
US9063901B2 (en) * 2012-08-16 2015-06-23 Hyundai Motor Company Method and system for preventing loss of trip data in vehicle
US11500848B2 (en) * 2017-07-20 2022-11-15 Continental Automotive France Method for determining the integrity of navigation data of a control unit of an automotive vehicle

Also Published As

Publication number Publication date
DE69810027D1 (de) 2003-01-23
EP0896276B1 (fr) 2002-12-11
JPH1153270A (ja) 1999-02-26
DE69810027T2 (de) 2003-08-14
JP3701776B2 (ja) 2005-10-05
EP0896276A1 (fr) 1999-02-10

Similar Documents

Publication Publication Date Title
US6169944B1 (en) Microcomputer-built-in, on-vehicle electric unit
US5460327A (en) Extended clock thermostat
US4411385A (en) Controller for the operation of heaters
US9561770B2 (en) Device and method for the voltage supply of an occupant protection system
US6460774B2 (en) Remote controller for air-conditioning apparatus
EP1074797B1 (fr) Procede de commande pour systeme de climatisation et systeme de climatisation
JP2000507793A (ja) 組み込みユニット及び／又は組み付けユニットの監視と制御のための装置を備えたコントロールボックス
US5596512A (en) Method of determining the condition of a back-up battery for a real time clock
US5075669A (en) Warning system for detecting burned-out condition of automotive lamps
US6003140A (en) Method and device for monitoring an electronic computing unit
EP0393631B1 (fr) Processus initial après coupure de la source d'alimentation et système de traitement correspondant
EP0769663B1 (fr) Appareil de climatisation à unités séparées et sa méthode de commande
JP4367275B2 (ja) データ記憶装置
JPH07239813A (ja) データのバックアップ方法
CN112146249A (zh) 空调器及其控制方法、系统、计算机可读存储介质
US7145444B2 (en) Circuit for controlling voltage in a tire-based unit of tire parameter sensing system and associated method
JP4419752B2 (ja) データ記憶装置
CN112805658A (zh) 电源检测电路控制方法以及电路系统
JP2001166017A (ja) 車載バッテリの電源電圧監視システム
JPH05276560A (ja) 給湯器のリモコンにおける瞬停時のデータ記憶方法
KR970003999B1 (ko) 자동차의 자기진단코드 백업장치 및 그 방법
JPH0756610A (ja) 制御装置のモード切換回路
JPS60176076A (ja) 電子複写機用定着装置の故障検知装置
US20010043072A1 (en) Programmable electronic flasher relays
GB2271680A (en) Back-up Arrangement of a Battery Power Supply for an Appliance

Legal Events

Date Code Title Description
AS Assignment

Owner name: ALPS ELECTRIC CO., LTD., JAPAN

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:HAYASAKA, SATOSHI;REEL/FRAME:009374/0224

Effective date: 19980722

Owner name: ALPS ELECTRIC CO., LTD., JAPAN

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:HAYASAKA, SATOSHI;REEL/FRAME:009298/0506

Effective date: 19980722

STCF Information on status: patent grant

Free format text: PATENTED CASE

FEPP Fee payment procedure

Free format text: PAYOR NUMBER ASSIGNED (ORIGINAL EVENT CODE: ASPN); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY

FPAY Fee payment

Year of fee payment: 4

FPAY Fee payment

Year of fee payment: 8

FPAY Fee payment

Year of fee payment: 12